Recently, white light emitting diodes (LEDs) are in the spotlight as a new lighting source achieving a substantial energy saving. A white LED device is manufactured by combining a GaN-based LED chip emitting blue light and a phosphor excited by the LED light to emit the light having a different wavelength from the LED light.
Recently, high-power white LEDs are being developed for general lightings or special lightings such as the headlights for vehicles. The high-power white LEDs have a local heat problem in a wavelength conversion member, such that various studies have been conducted for the heat dissipating property of the LED.
For example, in Patent Document 1 where the lens cover of the LED chip is formed with material that does not have an organic material, heat resistance of the lens cover is improved and heat conductivity is relatively high at 0.9 W/mK or more. In Patent Document 2, a light diffusing material is disposed at a predetermined position of a color conversion member (wavelength conversion member), such that the necessary amount of the light diffusing material can be reduced as compared with the case where the light diffusing material is distributed throughout the entire wavelength conversion member. In addition, concentration of the light flux of the LED is relaxed, such that the local heat of the wavelength conversion member can be prevented.    Patent Document 1: JP-A-2007-250817    Patent Document 2 JP-A-2009-130299